Fluorescent Gold Nanoclusters for Biomedical Applications

Abstract

Synthesis, characterization, and bioconjugation of fluorescent gold nanoclusters (FGNCs) are reported. The gold nanocluster is synthesized by etching gold nanoparticle. When the gold nanocluster is capped with reduced dipoic acid (DHLA, dihydrolipoic acid) that the nanocluster has the fluorescent property. The fluorescent gold nanoclusters have the emission in the range of 600 800 nm that is suitable for cell labeling, and its size and hydrodynamic radius are around 1.8 nm and 1.8 3.4 nm. The FGNCs can also be conjugated with desired biomolecules, such as biotin-PEG and avidin. In the preliminary data, the FGNCs can be taken nonspecifically by human aortic endothelial cells and the FGNCs conjugated with avidin can label specifically endogenous biotin within human hepatoma cells. Compare the FGNCs with semiconductor quantum dots and conventional organic dyes, the FGNCs are more biocompatible than quantum dots and more stable than organic dyes. So we believe that the FGNCs have great potential for biomedical applications.